mathematica中的带入式子叫做模式替换,运算符是斜杠点
比如你有个式子(a + b + c)/(2 a + b + c),
想把a=R*Cos[x + y]带入进去,就这么写
(a + b + c)/(2 a + b + c) /。 {a -> R*Cos[x + y]} ------>嘿,注意这里的斜杠点
输出
(b + c + R Cos[x + y])/(b + c + 2 R Cos[x + y])
另外,你的mathematica的图贴的真小,看得费劲死了,你可以点中你的程序右边的cell,就是那个小框,选中之后会变成蓝色,然后按Alt再按加号,就可以把式子调大了,Alt按减号就是减小字体。
有免费版本,除非你有钱买正版!
Mathematica激活指南_百度文库 http://wenku。baidu。com/view/80cd50a01ed9ad51f11df2c7
反解出 x 就行了。
Solve[y == (10^x - 10^(-x))/2, x, Reals] // Simplify
代码如下:
Manipulate[
With[{bsc = Take[{{0, 0, 0}, {0, 0, 14}, {0, 0, 20}, {0, 0, 25},
{1.7, 0, 30}, {7, 0, 32}, {10, 0, 31.5}, {13, 0,
30}, {15, 0, 26},
{13, 0, 20}, {10, 0, 17.5}, {4, 0, 13.5}, {2.5, 0,
11}, {0.33, 0, 7},
{0.2, 0, 2.5}, {0, 0, 0}}, t + 2],
sizes =
Take[{6.5, 14, 4, 2.3, 2.2, 2.2, 2.2, 2.2, 2.2, 2.2, 2.2, 2.6,
3.3, 3.6,
4.3, 6.5}, t + 2]},
Graphics3D[{color, CapForm[None], Opacity[opacity],
Tube[BSplineCurve[bsc], sizes]}, Boxed -> False,
PlotRange -> {{-15, 17}, {-15, 15}, {0, 35}},
ViewPoint -> {0, -5, 0},
SphericalRegion -> True, ImageSize -> {550, 400}]], {{t, 1,
“times”}, 1, 14, 1},
{{opacity, 0.7}, 0.1, 1}, {{color, Yellow}, ColorSlider}]